Industrial textiles for use in filtration, separation and conveying applications such as papermaking have been in use for many years. The vast majority of these fabrics are typically woven from polymeric yarns such as monofilaments using large industrial looms. Following weaving, the textiles are further processed for use in particular applications. At this point, a seam is usually installed so that the fabrics may be joined on the machine for which they are intended. Many seam constructions are known and have been used; however, most require a significant amount of highly specialized personnel and/or machinery. For such woven textiles, the fabric ends must first be prepared so as to free a portion of the component yarns from the woven structure; these yarns are then either rewoven with yarns from the opposite end to form a woven seam, or they are interlaced in one of various ways with seam devices which accept a joining pin or pintle, such as coils and the like. These seam constructions are costly and time consuming to prepare. Similar disadvantages of time and cost apply to nonwoven industrial textiles, such as those constructed from one or more layers of film.
WO 2010/121360 (Manninen) discloses a seaming element that can be attached to each of the two opposed fabric ends, thereby forming a seam in an industrial textile. The textile is typically cut straight across its width perpendicular to the intended running direction of the finished fabric. The seaming element is then bonded either over, or between, layers of the component yarns or film. The bonding method may include through transmission laser welding (TTLW). After the seaming element is bonded in position, the finished fabric is ready for installation on the machine for later use. The seaming element varies from 0.5 m to 6 m in length, and is made from a polymeric material. In one embodiment, the seaming element has a U-shape, which is slipped over each end of the prepared fabric and welded in place.
Other types of seaming element have been disclosed. For example, WO 2011/069258 (Manninen et al.) discloses a hinge type seaming element; PCT/CA2012/000701 (Manninen) discloses a fold-over type seaming element; PCT/CA2012/001138 (Manninen) discloses a multi-pin seaming element; and WO/2014/075170 (Manninen) discloses a roll formed seaming element including ridges.
U.S. Pat. No. 5,182,933 (Schick) and U.S. Pat. No. 4,942,645 (Musil) each disclose a fastener for securing the ends of belts, comprising upper and lower members that are connected at one edge by multiple arcuate loops that are separated by apertures. On the opposite edge, the fastener contains a series of webs that are riveted to the belt.
U.S. Pat. No. 4,719,788 (Musil) and Flexco®SR™ Rivet Hinged R9 Belt Fastener each disclose belt fasteners comprising an upper plate, a lower plate and loop shaped strap means for joining these plates. The upper or lower plate of these fasteners can be connected to the same plate of an adjacent fastener at rupturable bridges to form a fastener strip.
U.S. Pat. No. 6,216,851 (Mitas et al.) discloses a belt fastener element having upper and lower plates connected by arcuate hinge loops. Further, the lower plates are connected in a continuous manner while the upper plates are spaced apart.
It will be appreciated that during the bonding process, particularly when a TTLW bonding process is used, a reliable and high strength bond should be formed between the seaming element and the fabric component. TTLW requires intimate contact between the joining components in order to form a high strength bond. This can be difficult to achieve when a relatively large, solid object (such as the seaming element) is being bonded to relatively smaller and discrete units, such as the polymeric monofilament yarns of a woven fabric. Such yarns are often crimped and do not necessarily present a uniform, planar surface for welding. Similarly, nonwoven fabrics often have discontinuities and nonplanar irregularities, thereby reducing the necessary intimate contact between the seaming element and the nonwoven fabric.
It would be advantageous to render the bonding region of seaming elements flexible or compliant so that, during a bonding process, intimate contact can be made between the fabric components and the seaming element.
In addition, where a nonwoven textile is used, it would be advantageous to modify the attachment of the seaming element to the fabric so that the strength of the bond between the seaming element and the nonwoven textile is enhanced.